最近在看学erlang ,看到了字典这个demo ,把程序Copy出来和大家分享一下
-module (diction).
-export([new/0,lookup/2,add/3,delete/2]).
new() ->
[].
lookup(Key , [{Key,Value}|Rest]) ->
{value,Value};
lookup(Key,[Pair|Rest]) ->
lookup(Key,Rest);
lookup(Key,[]) ->
undefined.
add(Key,Value,Diction) ->
NewDict = delete(Key,Diction) ,
[{Key,Value}|NewDict].
delete(Key,[{Key,Value}|Rest]) ->
Rest;
delete(Key,[Pair|Rest]) ->
[Pair|delete(Key,Rest)];
delete(Key,[]) ->
[].